♦ Wisconsin and Missouri Lead Region. 67 



could get no satisfactory information, no work being now done 

 there. The mine is in a dilapidated condition, and little insight 

 can be obtained as to the true position of the ore. The limestone 

 and red rock meet each other very confusedly, there being near 

 the surface no regular line of contact. Fissures or openings ex- 

 tend vertically down between the rocks, and these are filled with 

 a mixture of iron ore, copper ore, clay and gossan, while above, 

 the surface is composed of gravel, consisting of pebbles of quartz, 

 chalcedony, and jasper mixed with red and yellowish clay. The 

 work over this small tract, which alone was found to contain the 

 ore, was carried on very badly. Instead of the whole surface 

 being stripped off clean to the rock, little holes and trenches were 

 dug all over it, and where the loose ore was found most abundant, 

 there the most digging was done. Sometimes the copper ore 

 forms nearly the whole material from the surface down even to 

 the depth of seven feet, the greatest thickness yet found to con- 

 sist almost entirely of ore. It lies in irregular shaped masses, 

 accompanied with hematite iron ore, into which it passes, and 

 these masses vary from pebbles up to the weight of seventy 

 pounds. They are scattered through the clay and gossan, or lie 

 sometimes in contact, and sometimes tending to a horizontal po- 

 sition. The clay and gossan are found to be worth washing for 

 the ore they contain. A little spot about twenty feet square, 

 where the ore was most abundant, is said to have produced as 

 much as all the rest. Little veins of copper ore, principally car- 

 bonate, may be seen running through the limestone, where it 

 comes to the surface, the thickest not more than half an inch 

 thick ; and on the granite under the other ores is often found a 

 thin plate of oxide of copper, incrusting the rock but not joined 

 to it. The grain of the limestone is here irregular, the seams of 

 stratification obliterated, and it is impossible to determine the 

 amount of disturbance it has experienced. Veins of " tiff" (calc 

 spar) are occasionally found in it, and with them small frag- 

 ments of oxide of copper interspersed, and crystals of pearl spar 

 and pargasite (?) 



A rotten vein, a foot thick, at about the point of contact of the 

 two rocks, consists of a curious altered mixture of them, with 

 particles of carbonate of copper scattered through the mass. 

 This sort of breccia is considered of some importance, as indica- 

 ting the proximity of ore, for almost exactly similar specimens 



